Packing for steam-turbine shafts



E. D. SPICER.

PACKING FOR STEAM TURBINE SHAFTS.

APPLiCATION FILED JAN. 4, 1917..

1,339,297, Patented May 4, 1920.

UNITED STATES PATENT OFFICE.

ELMER I). SPIGER, 0F WELLSVILLE, NEW YORK, ASSIGNOR T0 MOORE STEAM TURBINE CORPORATION, OF WELLSVILLE, YORK, A CORPORATION OF NEW YORK.

PACKING FOR'STEAM-TURBINE SHAFTS.

Application filed January 4, 1917.

To all whom it may concern.-

Be it known that 1, Emma D. SPIOER, a citizen of the United States, residing at IVellsville, in the county of Allegany and State of New York, have invented certaln new and useful Improvements in Packings for Steam-Turbine Shafts, of which the following is a specification. I

My invention relates to packing rings which are particularly designed to prevent the leakage of steam around the shaft of a steam turbine. 4

In packing rings for the above purpose long-wearing material such as carbon is used for packing element. It is the ob ect of this invention to generally improve the construction of the packing ring and particularly to provide an improved case for holding the carbon segments of the packmg ring to keep them from being broken when inuse. a

The above and other objects and the novel features of my invention will be apparent from the following description taken wlth the drawing which forms a part of this application.

The invention consists of structural characteristics and relative arrangements of elements which will be hereinafter more fully described and particularly pointed out in the appended claims.

In the drawings in which similar reference characters indicate the same parts in the several figures Figure 1 is a cross-sectional view of so much of the steam turbine as is necessary to show the application of my invention thereto.

Fig. 2 is a sectional view taken on the line IIII of Fig. 1. V

Fig. 3 is a perspective View of the im-. proved metal case for the carbon segments, and

Fig. 4 is a perspective view of a carbon lsegment which fits into the case shown in Referring to the drawing, 10 designates the rotary shaft of a steam turbine which passes through and rotates within an opening 11 in the fixed or stationary part or diaphragm 12. The edge 13 of the diaphragm faces the shaft 10 and has a packing groove 14 therein. The groove 14 has a recess 15 in its bottom which is for a purpose to be described later.

Specification of Letters Patent.

Patented May 4, 1920.

Serial No. 140,551.

The packing ring constructed according to this invention seats in the groove 14 and consists of a set of three substantially similar segments which have their ends in steam tight abutting relation.

Each segment consists of a solid segmental carbon block 16, similar to the one shown in Fig. 4. The inner face 17 of the block 14 is curved so that it will fit against the shaft 10 and provide a substantially steam tight joint. The top side of each block 14 has a recess 18 therein for a purpose to be described.

The case '19 which incloses the longitudinal sides and top of the block 16 is preferably made of sheet brass and is about the same shape as the block 16, except that the sides of the case are not quite as wide radially'as the side faces of the block 16, so that the inner edges of the cases will not 'engage the shaft 10 but will extend close to the shaft to protect the adjacent parts of the carbon blocks; against breakage. The metal cases may either be stamped out of sheet metal, the width being made slightly less than the thickness of the carbon block so as to make the block a force fit in the case; or the carbon block may be set up in a mold and a metal case cast around it. In the latter case the final outside dimen sions of the composite segment can be obtained by machining.

In the construction shown the carbon block 16 is a force fit in the case 19, which is of the same length as the carbon block. Both the carbon block and the case or cover are machined at both ends thereof so that they will form perfectly tight steam joints with the abutting ends of other segments. The side walls of the cases have slots 20 cut into them to increase the resiliency of the walls at their edges. The width of the cases is such that they will snugly fit against the opposite walls of the groove 14 and prevent leakage at those places.

While the segments abut against each other to form a continuous steam tight ring, each complete segment may move independently radially of'the ring or shaft as the carbon block wears. Each complete segment is pressed radially inwardly by a spring plate 21. The spring plate is fastened at its center to the top of the metal case 19' and the ends of the spring are bent outwardly and engage against the bottom of the groove 14; to support the segment in place.

The rivet 22 which secures the spring to the case 19 passes through both of those parts and its inner end terminates in a head 23 which fits into the recess 18 in the block 16 and prevents relative longitudinal movement between the case and the block. One of the cases 19 has a special fastening device 24 which secures the stud 25 to the up% per side of the case. This stud 25 is designed to fit into the recess 15 in the bottom of the packing groove and prevent the packing ring from turning with the shaft 10 or independently of the diaphragm 12.

The operation of the packing ring will be apparent from the foregoing description. It is obvious that the use of the same is not necessarily confined to steam turbines. WVhile I have shown and described the con struction in detail it is to be understood that modifications may be made therein without departing from the invention'as expressed in the appended claims.

What I claim is 1. A packing ring segment consisting of a solid segmental block of packing material, such as carbon, a segmental metal case having sides closely fitting said block to prevent the breaking thereof, said case and block being of the same length and having their ends machined so that they will form steam tight joints with the ends of the cases and blocks of abutting segments of a packing ring, a spring plate, and a fastening member securing said plate to the top of said case, said fastening member having a part projecting into a recess in said block whereby said block is prevented from moving longitudinally in said case.

2. In a steam turbine the combination with a rotatable shaft, of a member having an opening therein through which said shaft extends, the edge of said member facing the shaft having a packing groove there in and a recess in the bottom of said groove, and a packing ring seated in said groove and consisting of a plurality of separate and independent substantially similar segments having their ends in steam tight abutting relation, each segment comprising a segmental block of packing material adapted to bear against said shaft, a separate and independent metal case for each segmental block, a spring secured to the rear side of each case, the springs being seated in the bottom of said groove and pressing each of the packing blocks against the shaft independently of the others, one of said segments carrying a stud in said recess in the groove to prevent rotation of the packing ring, and means whereby said blocks are prevented from moving longitudinally in their cases.

In testimony whereof, I affix my signature.

ELMER I'D. SPICER. 

